Weird problem - need help
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Stage IV
Joined: Apr 2005
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Weird problem - need help
I am new to this forum. Sorry to start my first post with a problem and to ask for help, but I'm stumped. I am just a half-fast wrencher anyway, so maybe the solution is obvious to others here.
The bike in question is a 1997 Buell S3. The problem is that I am having an intermittent problem where the bike will just bog down completely, backfire and has no power when put under a load. While the problem is happening, the bike starts and revs fine...until I let the clutch out. Then tach drops to zero (sort of looks like an electrical problem or short), and the bike will stall or backfire - loud. Originally, I thought the problem occured only when cold, and went away once the engine had warmed up, as that is way it seem the first few times it happened. Tonight on my first spring ride it happened worse than ever before, when the engine was hot. After letting the engine idle, or sit for a few minutes, the bike starts and runs fine. There does not seem to be any pattern to when it occurs or what fixes it - sometimes when its idling or when its restarted. There are no other symptoms at any other time, everything runs great, good power etc.
Any ideas? Electrical? Some guy I was talking to said he thought it sounded like a short or bad battery...Trying to figure out why this would cause the backfiring. If you know the Buell, its a pretty simple bike. Obviously, the most puzzling thing is that its intermittent...I guess a short is intermittent, but I don't understand how a short would lead to the symtoms I see. If the battery is bad, why would the problem go away?
Appreciate any thoughts.
Steve
97 Buell S3
74 Norton 750 Commando
The bike in question is a 1997 Buell S3. The problem is that I am having an intermittent problem where the bike will just bog down completely, backfire and has no power when put under a load. While the problem is happening, the bike starts and revs fine...until I let the clutch out. Then tach drops to zero (sort of looks like an electrical problem or short), and the bike will stall or backfire - loud. Originally, I thought the problem occured only when cold, and went away once the engine had warmed up, as that is way it seem the first few times it happened. Tonight on my first spring ride it happened worse than ever before, when the engine was hot. After letting the engine idle, or sit for a few minutes, the bike starts and runs fine. There does not seem to be any pattern to when it occurs or what fixes it - sometimes when its idling or when its restarted. There are no other symptoms at any other time, everything runs great, good power etc.
Any ideas? Electrical? Some guy I was talking to said he thought it sounded like a short or bad battery...Trying to figure out why this would cause the backfiring. If you know the Buell, its a pretty simple bike. Obviously, the most puzzling thing is that its intermittent...I guess a short is intermittent, but I don't understand how a short would lead to the symtoms I see. If the battery is bad, why would the problem go away?
Appreciate any thoughts.
Steve
97 Buell S3
74 Norton 750 Commando
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From: Texas! Ya mean there's someplace else?
RE: Weird problem - need help
Only does it when you let the clutch out? Is the engine just bogging down, yet still running, or is it quitting? Usually, tho not always, a short will trip a circuit breaker or blow a fuse. Is this bike capable of storing fault codes? (Totally unfamiliar with Buells!)
Road Warrior
Joined: Dec 2004
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RE: Weird problem - need help
Heres my 2cents, possibly a loose or bad ground? Maybe the bike is grounding using the clutch cable (because the ground cable is loose)and its breaking down when the clutch is released? I would think the backfire from the exhaust would be a rich running condition, possilby caused by the ignition system breaking down and loading the cylinders. Is there black smoke while this running condition is present?
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Stage IV
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RE: Weird problem - need help
ORIGINAL: pococj
Only does it when you let the clutch out? Is the engine just bogging down, yet still running, or is it quitting? Usually, tho not always, a short will trip a circuit breaker or blow a fuse. Is this bike capable of storing fault codes? (Totally unfamiliar with Buells!)
Only does it when you let the clutch out? Is the engine just bogging down, yet still running, or is it quitting? Usually, tho not always, a short will trip a circuit breaker or blow a fuse. Is this bike capable of storing fault codes? (Totally unfamiliar with Buells!)
If I do not immediately grab clutch, the bike will stall, it is very quick, it does not just bog down (in relation to the amount I have let clutch out - even the small load will stall the engine) Also, even if I rev it to redline and let clutch out, it will do the same thing - almost stall immediately unless I grab clutch. Last night on the side of the road, I was able to test to see whether the problem was occuring without stalling the bike, but it took a little practice letting out very little clutch to get it down.
A Buell is a very simple, sport style machine with a standard Harley 1208 engine. Very few electrical accessories or systems - even the turn signals do not cancel! No fault codes there as far as I know. I'll check the book again.
In reply to Sincecrazy, the the best of my knowledge, there is no black smoke, however, last night it was dark[&:]
Two questions: Can a loose ground or other electrical problem cause the 'afterfire' . What is the process that causes this? I don' unnerstand!
I'll pull plugs today, but not sure why fouled plugs would cause intermittent symptoms...
They'll talk to ya and talk to ya and talk to ya about individual freedom. But they see a free individual, it's gonna scare 'em.
George Hanson -
Tourer
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RE: Weird problem - need help
Not sure about the S3, but I had a fault on My Buell X1, firstly intermittent cutting out which I traced to the sidestand safety switch sticking, I removed this and it was cured. Several weeks later a problem occoured similar to yours, the bike would start OK but as soon as it was put into gear it cut out, soon as I put it into neutral the electrics came back on and I could start it again. This was traced to the clutch safety switch on the handle bar, somehow the earth had become disconnected, the starter/ignition relays rely on these earths.which are sourced from the s/stand, clutch and neutral switches.
Your bike is probably relying on the neutral switch to hold in the ignition relay and because of this, as soon as you select a gear and the neutral light goes off, the earth is lost. and the power cut. I would definately check these switches are not sticking. I have removed both and earthed the cables directly to the frame and have not had any more problems ( touch wood)
Hope this helps
Lev
PS if you still have a problem, try http://www.badweatherbikers.com/cgib...cus/discus.cgi
Or http://www.ukbeg.com/frameset.htm Which has a very helpful Tech section
Your bike is probably relying on the neutral switch to hold in the ignition relay and because of this, as soon as you select a gear and the neutral light goes off, the earth is lost. and the power cut. I would definately check these switches are not sticking. I have removed both and earthed the cables directly to the frame and have not had any more problems ( touch wood)
Hope this helps
Lev
PS if you still have a problem, try http://www.badweatherbikers.com/cgib...cus/discus.cgi
Or http://www.ukbeg.com/frameset.htm Which has a very helpful Tech section
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Stage IV
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From: Midland, TX
RE: Weird problem - need help
I think Lev's probably right in that you have a loose ground wire somewhere in the system which would equate to power outages/shortages. Anytime you have that, the ignition system is going to misfire.
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Thread Starter
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Stage IV
Joined: Apr 2005
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RE: Weird problem - need help
Well, it seems like a consensus that the problem is electrical/loose ground. Can someone explain why the ground is only a problem under a load? Maybe thats Lev's clutch issue. I'm just trying to get this to fit together in my head before I start poking around. I can certainly clean and tighten all electrical connections. Maybe I can make it go away without understanding it exactly...this is not a bad thing...
I appreciate everyone's help.
I appreciate everyone's help.
Tourer
Joined: Dec 2004
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RE: Weird problem - need help
The sidestand switch and clutch switches let you start, but cut the engine as you try to pull away with a big bang.
The reason it happens under load? well Im afraid I cant answer that fully, but it could be as simple as the pressure your hands are putting on the contols is just enough to break the earth connection which IIRC earths by contact on the handlebar.
Ive been looking at my workshop manual and it says that the sidestand switches were not fitted to X1s until 2000, so if its the same for S3s this would just leave the clutch switch, which is an easy check, its the little plastic plunger thats pushed in and out when you operate the clutch lever, just a couple of screws and it comes off, the contacts inside can become loose so you can crimp them up,and put it back on , or do what I did and earth it to the mirror bolt. Im hoping this is the culprit, its an easy one to start with before going any deeper into electrickery!!
( please replace 'earth' with 'ground' where applicable, two nations divided by a common language and all that)
Lev
The reason it happens under load? well Im afraid I cant answer that fully, but it could be as simple as the pressure your hands are putting on the contols is just enough to break the earth connection which IIRC earths by contact on the handlebar.
Ive been looking at my workshop manual and it says that the sidestand switches were not fitted to X1s until 2000, so if its the same for S3s this would just leave the clutch switch, which is an easy check, its the little plastic plunger thats pushed in and out when you operate the clutch lever, just a couple of screws and it comes off, the contacts inside can become loose so you can crimp them up,and put it back on , or do what I did and earth it to the mirror bolt. Im hoping this is the culprit, its an easy one to start with before going any deeper into electrickery!!
( please replace 'earth' with 'ground' where applicable, two nations divided by a common language and all that)
Lev